Interesting US constitutional challenge to validity of church exemption from filing 990

In this article entitled “Atheist Activist Group Sues IRS Over ‘Preferential Treatment of Churches’” in the Christian News Network it discusses the exemption that churches having to filing the US form 990 and how one group is challenging that preferential treatment. In Canada, generally churches along with all other registered charities have to file the T3010. The article also describes the same group challenge housing benefits for the clergy in the US and lack of IRS enforcement against churches who engage in partisan political activities.